The Siemens 3RH2916-1FA22 is a SIRIUS auxiliary switch block designed to snap onto the front of size S00 contactor relays and power contactors (3RT2 series). It adds two normally-open and two normally-closed instantaneous auxiliary contacts to the base contactor, giving you four poles total for feedback, interlocking, or PLC input signals. Rated at 6 A at 230 V AC-15 for inductive solenoid loads, it also carries 10 A at 24 V AC-15 and 1 A at 690 V AC-15 — covering the full control-voltage range you'll see in a 400 V panel. Snaps onto the front of the contactor — no tools, no DIN-rail space consumed beyond the contactor itself. The 36 mm width matches the S00 contactor footprint, and the 43.7 mm depth stays within the contactor envelope, so panel layout doesn't change when you add it.
Contact reliability and mirror contact function
This switch block also provides a mirror contact function per IEC 60947-4-1 when used with the 3RT2 contactor. That means one of the N/C contacts mechanically mirrors the main contactor's N/O power poles — critical for safety circuits where you need positive indication that the main contacts have opened before allowing access to the load.
RoHS compliant per the substance prohibition date of October 1, 2009. Surge voltage resistance rated at 6 kV, which covers the impulse withstand requirements for 400 V industrial control circuits. Terminal capacity accepts 2 × (0.5 to 1.5 mm²) solid or 2 × (0.75 to 2.5 mm²) stranded with ferrule, or 2 × (20 to 16) AWG solid / 2 × (18 to 14) AWG stranded — covers the wire sizes you'll typically run to auxiliary contacts in a control panel.